1. Technical Field
The present invention is a panel board assembly for mounting valves used in a hydraulic system. More specifically, the panel board assembly is made up of interlocking self-supporting modules.
2. Prior Art
Conventional panel boards for fluid control valves were large steel plates that were custom bored to receive valves on one side and hydraulic fittings on the other. Each panel board was custom made to suit a particular set of valves. If a hydraulic system was changed to include new valves it was necessary to layout, bore and tap additional holes in the panel board. This operation was time consuming and resulted in considerable machine downtime. Since hydraulic valves frequently have different port arrangements, changing a valve to one of a different type frequently required drilling new holes in the panel making the units difficult to adapt to changes in the hydraulic system. As will be readily appreciated, such panel boards were heavy which made them difficult to install or relocate.
U.S. Pat. No. 2,927,602 was directed at overcoming some of the above problems encountered by conventional panel boards. The patented construction provided a panel board assembly having a plurality of standardized panel modules which were fastened together to form a panel board assembly. The modules were held together by bolts which extended through holes formed in flanges formed about the periphery of the modules. This panel board assembly was heavy and time consuming to construct.
U.S. Pat. No. 3,561,469 represents an improvement over the prior patent in that it provides for a panel board assembly made up of metal or plastic modules that are retained in H channel members. The H channels are provided on all sides of the panel board assembly and between rows of modules. The H channels were required to support the modules in the panel board assembly. The modules must be formed to close tolerances to fit precisely within the H channels since an oversized module would not fit within the channel and an undersized module was loosely held by the frame causing adverse effects on the performance of the hydraulic system. The panel board was complex in construction and required a multiplicity of parts to fabricate a single panel board.
Applicant, in an attempt to solve the problems of the prior art, had previously produced a panel board made up of modules as shown in FIG. 2. The modules included flanges that allowed the edges of adjacent modules to interlock each other in one direction. While this construction exhibited certain advantages over the prior art, the panels were not self-supporting during assembly causing problems in the construction of the panel board. In addition, since each side of a panel only interlocked with adjacent panels in a single direction the fully constructed panel board assembly was unstable.